1. Field of the Invention
The present invention relates to a connector examining device for examining attachment conditions of terminals of connectors interconnecting wire harnesses or electrical equipments used in vehicles and the like.
2. Description of the Related Art
For wire harnesses used for wiring of an electrical equipment in vehicles, a connector is used for interconnecting wire harnesses or connecting a wire harness with an electrical equipment. The connector generally has a housing formed of synthetic resin and female or male terminals accommodated by terminal containers formed in the housing. The terminals are engaged with the housing in the so-called housing lance system. When housings of a female connector and a male connector are engaged with each other, the female and male terminals are mated to attain electrical connection.
The housing lance system is a technology according to which an elastic engagement arm integral with the housing projects toward the inner space of the terminal container, and the engagement arm is engaged with an aperture or an abutment of an electric contact portion of the terminal so as to prevent the terminal from slipping out. In the course of inserting the terminal into the housing, the engagement arm comes in contact with the terminal and is elastically transformed. When the terminal is perfectly inserted, the engagement arm restores its original shape and engages with an aperture or an abutment of the terminal. Thus, perfectly inserting the terminal in the housing, the engagement of the terminal is automatically attained.
However, the engagement arm cannot be formed so large, and hence, repetitive attachment/detachment operation causes the male and female connectors to be damaged, and eventually the terminal may drop out of the housing.
In recent years, a connector having a double engagement arrangement has been widely used. Such connector has an engagement member engaging with the terminal. The engaging member is fitted in the housing from its side after the terminal is inserted so as to attain an extra engagement of the terminal in addition to the housing lance system. Such a connector is disclosed, for example, in Japanese Examined Patent Publication No. 23391/1992.
The connector disclosed therein has a through-hole formed at a side of the housing, into which an engagement member is inserted. The engagement member is put under a temporary engagement in such a retracted position that allows insertion of the terminal before it is inserted in the housing. After the terminal is inserted in the housing, the engagement member is pushed into it to attain the double engagement.
In this arrangement, the engagement member is temporarily engaged with the housing in advance, and therefore, the housing and the engagement member can substantially be handled as one element. Hence, inventory management and the like can be advantageously simplified.
For the connector having the double engagement arrangement as mentioned above, however, an operation of inserting the terminal in the housing and an operation of pushing the engagement member into the housing must be conducted. Then, in course of producing a large amount of wire harnesses, the pushing operation of the engagement member may fail or the insertion of the engagement member may be imperfect.
Additionally, a stroke length of the engagement member between a position of the temporary engagement and a position where the member is completely pushed is at most about a size of the terminal container, and therefore, it is difficult to determine if the operation of pushing the engagement member has been perfectly conducted. Furthermore, a connector without perfect double engagement is not reliable in the engagement of the terminal, and accordingly, a wire harness is not reliable.
At the final stage of production of the wire harness, a conduction check of the connector is normally conducted. The connector conduction check is performed to check if a terminal is inserted well in the housing, or if a terminal is crimped well to an electric wire. If the terminal is not inserted in the housing, the terminal is inserted in an inappropriate position, or the terminal is imperfectly crimped, an electrical equipment for an automobile causes malfunctions. Thus, the conduction check is essential in producing the wire harness.
An examination device for the connector conduction check has a connector receiving portion for holding a housing and a detector portion provided opposed to the connector receiving portion. The detector portion is provided with detectors to be conductive with terminals within the housing. For example, the connector receiving portion is fixed while the detector portion is slidably attached so that is can be displaced close to or apart from the connector receiving portion.
When the detector portion is displaced close to the connector receiving portion with the housing being attached to the connector receiving portion, the terminals within the connector housing and the detectors provided in the detector portion respectively come in contact with one another, and electric conduction is obtained between them. If the terminal is not inserted in the housing or the terminal is not crimped well to an electric wire, it is checked that the conduction is in a bad condition. Thus, conditions of attachment of the terminal, crimping of the terminal, and the like can be checked depending upon if conduction is obtained between the detector and the terminal when tile detector portion is close to the connector receiving portion.
Japanese Examined Patent Publication No. 56786/1990 discloses a technology which employs the connector examining device as stated above to detect imperfect insertion of the engagement member. According to the technology, a detecting unit for detecting a level difference of the engagement member from a surface of the housing is provided with a connector receiving portion.
The detecting unit is, for example, implemented by an arrangement where a detection pin protruding/retracting is provided with the connector receiving portion at a position opposed to the engagement member. If the engagement member is completely pushed into the housing, it never protrudes from the surface of the housing, and a displacement of the detection pin is small. If the engagement member is inserted imperfectly, however, it protrudes from the surface of the housing, and the displacement of the detection pin is large.
Thus, by such arrangement where the greatly displaced detection pin lights a lamp, for example, the examiner can learn that the insertion of the engagement member is imperfect.
In the above-mentioned prior art technology, however, if it is detected that the insertion of the engagement member is imperfect, the examiner has to detach the housing from the connector receiving portion, push the engagement member into the housing, and then attach the housing to the connector receiving portion again to renewedly check the connector. Thus, the prior art technology as mentioned above has a disadvantage that an operation in the process of the conduction check is complicated, and the productivity of the wire harness is necessarily degraded.